Joint for road construction



4l.. B. JoHNsoN f 2,242,1610

JOINT FOR ROAD CONSTRUCTION Filed Aug. 4, 1939 May 2o, 1941.

Patented May 20, 1941 i.) N l 'l' E E STATE S i PAT@ i 2,242,610

JOENT FOR-ROAD CONSTRUCTIQN Louis-1?. Johnson, Baltimore, Md

Application August 4, 1939, Serial No. '288,420

2 A'Clailrlsh My present invention relates to joints forfroadways and more particularly .to lsuch ya joint Aadapted to be positioned above the sub-grade of the roadway to produce a fault or crack in the concrete of the roadway.

One ofthe primary objects ofthe invention is the formation of a joint in the lform of interconnected units whereby each unit when `placed on the sub-grade of the roadway will -position a joint-forming strip a predetermined distance above the roadway.

Yet another aim is the construction of a joint having a plurality of spaced transversely AeX- tending hook-shaped supports for thejjoint strip whereby said supports will not only position'the joint strip a predetermined distance above the roadway but will `also function as reinforcement for the concrete and additionally tend to tie together the sections constituting the roadway.

Still a further purpose of the 'invention is the formation of a joint including a flexible joint strip whereby the joint finds application in the building of curves in the roadway.

The above and other aims and objects will be apparent from the detailed description hereinafter appearing when taken in conjunction with the appended drawing forming a part hereof to which reference is now made and in which- Fig. l is a perspective view of a road joint unit embodying the invention and showing a jointforming strip and its supports.

Fig. 2 is a sectional view through a portion of the roadway showing the joint unit positioned on the roadway.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is a plan view showing how the joint strip may be flexed for use in building a curved section of roadway.

As is well known, in the building of concrete roadways of full width construction as distinguished from the lane-at-a-time method, a center line joint should always be provided. It has been found that a very eiiicient joint of the type indicated is produced by forming a fault or crack in a predetermined position in the road. The instant invention is concerned with a unit adapted to be placed on the sub-grade of the roadway preferably to form a longitudinal joint in the road when a number of units are joined end to end.

Referring now to the drawing wherein a preferred embodiment of the invention is illustrated, the reference character U represents a joint unit in its entirety formed of proper gauge steel or the like,.said unit [being characterized by-athin flexiblesteel strip .I0 of Aany preferred width. vIn practice, .strip which is about one-eighth inch thick, two inches wideand ve feet long hasbeen found .to be highly practical. The strip il!) :is adapted .tobe mountedy in a vertical plane normal to the `sub-'grade S of a roadway R 'within the concrete C thereof. To support the joint-strip AI in the .manner .indicated a pair 'of .similar longitudinally-spaced transverse steel supports II .are employed, the distance between theisupports .being preferably. about two-andfa-.halffeet Each support II is .aboutone-half 1inch thick, and is characterized by a horizontal 'section l2 terminating in similarinwardly curved end Asections t3, 13a. It will 'be noted that the :bottom edge YM 'of strip il) :.rests on the .upperzsurfaces of :each .horizontal section IJ2 Vcentrally of its curved ends I3, I3a, and is welded thereto as indicated at I5. A plate l of an approximate size of two inches square is welded as at I'I to the bottom edge of each curved end I3, I3a. The plates I6 are adapted to rest on the subgrade of the roadway R and the strip IIl will ibe held by supports I3, I3a above the subgrade a predetermined distance to form a longitudinal joint between road sections I8 and I9 in a manner to be shortly described. Welded as at 20 to each horizontal section I2 of supports II and adjacent flexible strip I0 is a washer 2I adapted to receive a pin 22' or the like therethrough. One end of each strip I0 carries a sleeve or the like 22 for receiving the free end 23 of the strip l0 of an adjacent unit U, see Fig. 3. v

In forming a longitudinal joint in the roadway a unit U is positioned on the sub-grade Sl of the roadway in the manner illustrated in Figs. 2 and 3, and each unit is held in place against displacement by means of pins 22' passing through the Washers 2| welded to each unit. It will be noted that the flexible strip IIJ will now be held `a predetermined distance above the sub-grade S and with the dimensions of the unit given as illustrative, this distance will be about four inches. Succeeding units U are also placed on the sub-grade S in end to end relationship, the units being held in alignment by means of the sleeves 22. After the units are in place, concrete C is poured on the sub-grade over the units to form road sections I8 and I9. When the concrete hardens irregular cracks 30 and 3| are formed respectively below and above the strip Il] and substantially in alignment therewith. These cracks 30 and 3| constitute an efficient joint as will be understood by those skilled in the art. By means of the curved ends I3, I3a not only is the strip positioned above the sub-grade S, but the concrete C is reinforced and the road sections I8 and I9 tied to each other. By making the strip I flexible it is possible to provide for a curve in the roadway, the unit U being iiexed as shown in Fig. 4 to bring the supports II in intersecting planes instead of parallel planes when the strip I0 is in normal or uneXed condition. In some instances it is not desired to have theuniting function of the two curved ends I3, I 3a of a support I I and in such case one of the curved ends I3 or I3a is eliminated by making same a continuation of horizontal portion I2 and in the same plane therewith. The uncurved end may then be supported by various means until the concrete is poured and the supports will then be removed. The crack 3| may be filled with material such as tar or the like up to the level of the sections I8 and I9.

While the invention has been described in detail it will be apparent that various changes may be made in the specific embodiment thereof illustrated. Thus, the dimensions given are to be considered as purely illustrative and although the different elements of the units are described as welded together they may be xed to one another by other means and in other ways.

It will also be appreciated that the rigid unit described eliminates the assembling by hand of constituent parts which has been the practice heretofor. Also, it will be understood that all the units will remain in perfect alignment at all times, particularly during construction of the roadway and will produce a true perfectly aligned joint. Another great advantage is that the unit forms a much better bond of the concrete to the supports or tie bars due to the curved ends thereof which is not possible with the use of straight tie bars and supporting means therefor.

It will also be evident that the units are easiily handled and readily placed in operative position on the roadway thus constituting a material saving in labor and costs all of which are highly desirable. All of the above features provide a unit with more bond which is preferred from an engineering standpoint.

What I claim and desire to secure by Letters Patent is:

1. A joint for roadways comprising a flexible strip producing a joint in the roadway, means for Y supporting said strip, said means comprising independent spaced rods xed to and extending transversely of said strip, each rod comprising a horizontal portion to which the strip is secured,

said horizontal portion terminating in inwardly curved and downwardly extending ends, a horizontal plate secured to each inwardly curved portion forming an extension thereof to rest flatly on the sub-grade of the roadway, and means for holding the joint in xed position on the subgrade.

2. A joint for roadways comprising a flexible strip producing a joint in the roadway, means for supporting said strip, said means comprising independent spaced rods fixed to and extending transversely of said strip, each rod comprising a horizontal portion to which the strip is secured, said horizontal portion terminating in inwardly curved and downwardly extending ends, a plate secured to each end to rest atly on the subgrade of the roadway, and means comprising washers secured to the rods and removable pins passing through the washers for holding the joint in xed position on the sub-grade.

LOUIS B. JOHNSON. 

